Control of frictional coupling of transmembrane cell receptors in model cell membranes with linear polymer spacers.

The planar plasma membrane model with linear polymer spacers with defined lengths enables the control of the frictional coupling between incorporated transmembrane proteins (human platelet integrin) and the solid substrate. This mimics the viscous environment provided by the extracellular matrix of cells. The friction coefficient can be calculated quantitatively from the diffusion coefficient of integrin, measured by fluorescence recovery after photobleaching. The obtained results demonstrate a clear influence of the length and lateral density of polymer chains on the mobility of transmembrane proteins.